Can't get r_fullbright working, heeelp

Hi, I'm trying to enable fullbright but when I type "r_fullbright 1" the console says "Changes will be applied upon restarting..."

But restarting what ? I tried with "cvar_restart", nothing.
After restarting CoD, no changes and still on "0".
Same problem on 1.1 and 1.5 patches :/

I tried with King-Orgy's Cod1Bot, but enabling fullbright does nothing, is it normal?

Is r_fullbright really built in cod 1 ? Hope someone could know that.. thanks.